Device for supplying hot air to a furnace



June 23, 1936. E, uKs 2 ;045,194"T DEVICE FOR SUPPLYING HOT AIR o A FURNACE Filed June 3, 1935 Ralf;

IN VeNTOR Patented June 23, 1936 UNl'iED ST ETEN'E OFFE Robert Emile miles, Paris, France Application June 3, 1933, Serial No. 67%,239 In France January 23, 1933 3 Claims. (oi. ire-ts) This invention relates to apparatus for supplying heated air to a boiler furnace or the like, in which a conduit .is arranged above the bridge and, if desired, at the sides of the furnace, said conduit having lateral orifices of equal area, the arrangement being such that approximately equal quantities of air are discharged from the orifices.

In known apparatus of the above kind the conduit was of one sectional area throughout, the lateral orifices being fitted with tubes which projected to a greater or less extent into the interior of the conduit and terminated in bevelled ends facing the air current, the obliquity of these ends increasing from the source of supply. Another apparatus of the above kind has been proposed in which the conduit comprised a number of similar elements having circular holes with inclined surfaces at one part sloping from front to back into which open small lateral orifices, the conduit being divided into sections by diaphragms with openings decreasing in size towards the back.

The present invention consists in an apparatus of the kind first referred to in which the sectional area of the air passage or conduit diminishes from the point of entry, the outer edges of curved elbow branches leading to the orifices, projecting into the interior of the main passage to ensure an equal distribution of the air.

The invention also consists in the further features as hereinafter described and defined in the appendant claims.

An apparatus according to the invention is represented by way of example, in the accompanying drawing, of which:-

Figure 1 is a diagrammatic perspective view showing the apparatus in the course of assembly;

Figure 2 is a horizontal section of the headeron the line 22, Figure 1;

Figure 3 is a cross-section of the header on the line 33 of Figure 1;

Figure 4 is a horizontal section of the header as in Figure 2, the preheater and the distributor being shown separated;

Figure 5 is a front view of the preheating memarranged a grate 3 which serves as a support for the fuel.

Before the completion of the walls l, 2 and 2 of the furnace, the apparatus for the supply of hot air is inserted at a suitable distance 1 above 5 the grate 3 (the height of three bricks for example) in the bridge 9 and in the side walls 2 and 2 The apparatus is built-up in the following manner:-

A fan l operated by an electric motor 5 blows air into a principal conduit 8 which is divided into three elementary conduits l 77 and '5 respectively feeding headers 8 8 and 8 mounted on the bridge l and in the side walls 2 and 2 of the furnace.

Each header comprises two members, an external part 9 intended for the preheating of the air and an internal part or distributor it connected to the former part and ensuring the distribution of the hot air over the furnace.

The external part or preheater 9 is itself divided into -a number of sections e e assembled together by the screw-threaded sleeves ll; this construction facilitates the manufacture and assembling of these elements in situ.

The external part or preheater 9 has in its length different sectional areas of the air passages 5 S 5 S which become smaller in proportion to their distance from the point of arrival of the air; in this manner the currents of air have pressure losses which therefore give substantially equal pressures at the feed outlet orifices I2 12 E2 which are provided at the inner face of the preheater member, and are of substantially equal size.

Under these conditions, there is obtained a regular distribution of the hot air under pressure throughout the whole furnace and, consequently,

a regular combustion of the whole mass of fuel.

The orifices l 2 l2, l2 are connected with the different sections S S S by curved elbow connections I3 l3 the outer edge it of each of which, directed towards the current of air ,f, forms a projection and compels a portion of the currents of air to pass to the corresponding orifice; each edge M of the elbow connections I3 hi3 thus takes from the main stream a cer- There is thus ensured a regular deduction from and a guidance of the whole stream of air supplied to the header, which stream is divided and distributed equally in all the outlet orifices I2 The outlet orifices I2 I2 I2 and I2 in the header 9 open into distribution orifices I6 I6 I6 and I6 in the distributor in these orifices being respectively connected together by means of tenons I1 I1 around the outlet orifices I2 l2 that engage mortises I8 i8 in the distributor orifices.

After the assembly of the two parts 9 and ID of each header, they are secured together by means of screws 29 for example; this method of assembly enables the eventual dismantling of these headers in order that they may be easily cleaned, repaired and re-assembled.

The orifices I6 I6 of the distributor have the shape of a hopper the bottom faces 20 of which are inclined downwardsi. e. towards the mass of fuel-the upper faces being horizontal so that the currents of air spread out and are directed,

towards this mass of fuel which is situated on the grate 3 at a lower level than that of the oriflees I6 I6 For the purpose of controlling the pressure of the air passing in the apparatus, one of the head- 'ers 8 8, 8 for example the side header 8 has at its front end a pipe union 25 to which is connected a pipe 26 that leads the pressure air to a manometer 21; there is also a regulating device, such as a regulatable resistance 28, which controls the speed of rotation of the electric motor 5 and, consequently, that of. the fan 4, thereby enabling the pressure of air sent into the furnace to be regulated.

The whole of this controlling device is arranged on a supporting plate 30-fixed on the front face of the furnace.

Summarizing, there is described an apparatus for supplying hot air to a furnace, which is of simple construction, is readily assembled and is very easily inspected and repaired. Moreover, the controlling and regulating devices enable complete combustion of the fuel under optimum conditions of regularity to be ensured.

While a particular construction has been described in the foregoing statement, it is clear that many modifications can be made in the construction and arrangement of the parts without departing from the scope of the. invention as set forth in the appended claims. 5

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:--

1. In a device for supplying hot air to a boiler furnace in combination an air blower, power driv- 10 en means for same, a conduit forming a main passage adapted for insertion in the brickwork of the furnace above the grate, curved elbow branches from said conduit leading to lateral outlets in the face of the conduit, outer edges on the 15 respective elbows which project into the interior of the main passage, the said projecting edges being connected with the next outlet passage by inclined surfaces, in which the conduit comprises two portions, a heater member within which is 20 the main passage and the elbow branches and a distributor provided with lateral distributing orifices coinciding with the elbow branches mortice and tenon joints being provided at the adjoining faces between the heater and distribution mem- 25 bers, and securing bolts for connecting said portions together.

2. In a device for preheating and distributing air to a furnace combustion chamber, a preheating conduit with walls of substantial thickness 30 and an inlet, the internal diameter of said conduit diminishing as the distance from the inlet .diminishes and outlets toward said combustion chamber, a distributing member having inlets registering with said outlets and outlets from said 35 distributing member flaring toward said combustion chamber, said preheater and said distributing member being dove-tailed, together, on their v contacting surfaces and bolts securing said two ROBERT EMIfLE LUKS. 

